The recent discovery of a potent new class of herbicidal compounds, known as the imidazolinone compounds, has resulted in considerable field testing of these compounds for various uses worldwide.
Novel imidazolinyl benzoic acids, esters and salts, their preparation and use are disclosed in U.S. Pat. Nos. 4,188,487; 4,297,128 and 4,554,013 and pending application for U.S. Letters Patent Ser. Nos. 579,224, and 629,296, while various novel pyridine and quinoline imidazolinone compounds are described in pending application for U.S. Letters Patent Ser. No. 382,041, and U.S. Pat. Nos. 4,647,301, 4,650,514, 4,608,079 and 4,701,208.
The free acids of these compounds may be represented in general by formula I below ##STR1## wherein A is CH, N or N.fwdarw.O;
W is oxygen or sulfur; PA0 X is H, halogen, methyl or hydroxyl; PA0 Y and Z are each hydrogen, halogen, C.sub.1 -C.sub.6 alkyl, hydroxyloweralkyl, C.sub.1 -C.sub.6 alkoxy, C.sub.1 -C.sub.4 alkylthio, phenoxy, C.sub.1 -C.sub.4 haloalkyl, nitro, cyano, C.sub.1 -C.sub.4 alkylamino, diloweralkylamino or C.sub.1 -C.sub.4 alkylsulfonyl group; or phenyl optionally substituted with C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy or halogen; difluoromethoxy, trifluoromethoxy, 1,1,2,2-tetrafluoroethoxy, C.sub.3 -C.sub.8 straight or branched alkenyloxy optionally substituted with one to three halogens, or C.sub.3 -C.sub.8 straight or branched alkynyloxy optionally substituted with one to three halogens; and, when taken together, Y and Z may form a ring which may optionally be substituted, in which YZ are represented by --(CH.sub.2).sub.n --, --(CH).sub.n --, where n is an integer of 3 or 4, and when A is N or N.fwdarw.O YZ may also be --(CH.sub.2).sub.2 --Q-- or --(CH).sub.2 --Q--, wherein Q is oxygen or sulfur, with the proviso that X is hydrogen; PA0 R.sub.1 is C.sub.1 -C.sub.4 alkyl; PA0 R.sub.2 is C.sub.1 -C.sub.4 alkyl or C.sub.3 -C.sub.6 cycloalkyl; and when R.sub.1 and R.sub.2 are taken together with the carbon to which they are attached they may represent C.sub.3 -C.sub.6 cycloalkyl optionally substituted with methyl.
Acids of formula I may be formulated as aqueous solutions of a water soluble salt of the acid, as they have limited solubility in non-protic organic solvents. The preparation of organic solvent emulsifiable compositions of formula I acids by utilizing C.sub.8 to C.sub.22 tertiary alkylamine salts of the acid which are soluble in organic solvents is described in pending application for U.S. Letters Patent of B. Cross and W. Steller, Ser. No. 734,212 filed May 15, 1985.
While aqueous solutions of imidazolinyl acid salts are suitable for a variety of general herbicidal uses, it has been found that upon aging for extended periods of time and/or exposure to elevated temperatures, that aqueous solutions of these acid salts exhibit loss of potency.
It is an object of this invention to provide novel aqueous compositions of water soluble formula I herbicidal acid salts which are physically and chemically stable for extended periods of time over a wide range of temperatures.